Flight Modeling vs. Flight Handling.

[CaptainDoggles]

Interesting topic indeed!

I don't buy it though, or perhaps just not the car analogy.

To put it in a context that I can relate to being someone involved in motorsport of the 4 wheeled variety...

You can have two cars with identical performance numbers across the board, top speed, braking, acceleration, lateral Gs, etc... Yet one will have to be bullied into doing it and the other will behave as if connected directly to your brain.

If two cars have identical accelerations then they'll hit the same speed at the same time. Period. If the driver of one feels like he has to "bully" the car into doing it then that's his problem. Just a problem with his perception - because we already know the car is doing it just as well as the other car. If it didn't, then the accelerations would not be identical.

As far as this can relate to aircraft, well, I'm not sure what ElAurens is advocating exactly, but it does raise the issue of how to simulate what basically boils down to a pilot's opinion.

Being an engineer, my belief is that the nebulous qualities that we call "handling" or "feel" will show up when we consider things such as the aircraft's stability. For example the Spitfire was widely considered to be a forgiving aircraft but (test) pilots complained that the early versions "did not have enough elevator authority" and that it was difficult to control the aircraft, pitch-wise. When the issue was investigated it was found that the aircraft had a very narrow longitudinal stability margin.

I struggle to imagine a concept that can't be quantified, or related to some measurable quantity in some way.

[BP_Tailspin]

Here we go .....

[Blackdog_kt]

I think everyone that posted so far is correct in some way and touches upon all the main aspects of the topic.

I can certainly feel what ElAurens says, but that's through years of perception under controlled conditions (same control profiles, peripherals, software used, etc): in the previous IL2 series it didn't feel the same doing 500km/h in a 109 and doing the same in a 190, but it took quite some time to notice it.

In a similar fashion, when i first took up a 111 in CoD it felt much heavier and full of inertia than whatever bomber i had ever tried in IL2, but in a way that didn't feel uncanny. To the contrary, it felt just right and i had the feeling that the extra weight and size really showed.

I think the variables are too many and while it's true that i can't think of something that can't be quantified and measured (like Doggle says), maybe we don't have the technology to take advantage of it yet. Of course it's mostly fundamental newtonian mechanics at the speeds and masses we are talking about, but how many consecutive higher order derivatives of a certain function can a current PC compute per second and at how many instances and points across the aircraft's surface before melting?

It's also difficult to quantify objectively because of the same reasons: few or no surviving aircraft, probably different in handling than when they came off the line after all these years (refurbishments, weight changes due to modern avionics installed per ATC rules, removal of guns, etc), a dwindling amount of veterans who all have their subjective opinion (depending on their flying habits) and a multitude of sim fliers with millions of combinations of different controllers and input curves.

It's a nightmare


I think that technology-wise Xplane is probably the closest one can get to having a wind tunnel emulator running on a PC (as long as the individual flyable is also done to a high standard to take advantage of the sim's engine in full), but sadly it will be some time before we see such technology in combat sims: it's so taxing that with full multi-core support in Xplane 10, a current PC can not run more than 4-6 AI aircraft with the same FM accuracy at the same time without noticeable performance loss. In fact, there are people who take Xplane flyables, simplify their FMs and reissue them as AI-only aircraft to populate the game world.

P.S. Very interesting topic

[CaptainDoggles]

Originally Posted by Blackdog_kt

in the previous IL2 series it didn't feel the same doing 500km/h in a 109 and doing the same in a 190, but it took quite some time to notice it.

I agree with this, but it comes back to perception/opinion. Maybe I feel the 109 "feels faster" and you have the opposite impression.

Is that even possible to quantify, let alone model?

My gut says no, because it's probably not an actual difference in the aircraft, just a perceived difference.

[Les]

No two machines of any type are exactly the same, especially when they're of a more complex construction like a vehicle is, and especially after they've been subject to wear an tear.

Machines are built to operate within varying internal tolerances, and so while two vehicles may be superficially identical, there can be enough differences in all their variables to give each one a unique character or feel if one becomes familiar enough with them. Lubrication, hydraulics, different construction materials, different levels of wear and maintenance, and faults that aren't worth ironing out, can all vary and line up in such a way as to become noticeable in subtle or even obvious ways.

Simulations may never get down to that level of complexity and may always have to provide a single generalized representation of a machine, but who knows, one day all the variables might be able to be generated and result in genuinely individual virtual vehicles.

I think though that such a level of complexity is only part of what would add up to a more accurate 'feel' when flying in a game or sim, with most of it being dependent upon an equally accurate depiction of the physical interaction of the plane with the atmosphere around it.

That space the plane's fly around in isn't empty. It's a constantly changing set of influences that are mind-bogglingly complex and variable, and while a lot of them can be depicted, visually and even via force-feedback, I'm not sure how complex the depiction of the weather and atmosphere would have to be before it allowed one to get a real sense or feel of actual flight. Some would say it's already been done in some ways, and some would say it will never be possible without using a hardware system that somehow allows you to experience the changes in g-force and air pressure that can occur in flight.

With computer simulations we're very dependent upon audio and visual cues/clues, and somewhat dependent upon force-feedback effects to give us an idea of what the plane is doing and being subjected to from outside, and so, as complex as that can ever be, it's always going to be somewhat limited in what it can convey. But I'm of the opinion that even without the added sensory input that you can get in real-life, there's still scope for a more realistic and complex simulation of the machines and their environments than what we've experienced so far.

The sensation of flight is something that results from such a complex arrangement of factors that there are bound to be lots of new breakthroughs, all giving a more accurate experience than the last, as the simulation technology itself becomes more complex and able to recreate things in finer detail.

The sights, the sounds, the control inputs, the machine and environment systems, all need to keep developing and improving in unison, as indeed they have been over the years. But people need to keep supporting the flight-sim genre of games and simulations to keep those developments and improvements happening. I think for as long as people are using computers there will always be someone somewhere using them to simulate flight. I think it's as irrepressible an urge as the desire people have to fly for real, but if the rest of us want to enjoy the results of those works of passion, we need to make sure we give ourselves that opportunity by supporting those we know of who are currently pushing the technology further towards that goal of a more complete and accurate flight-sim experience, wherever they may be.

[hiro]

I saw this video my brother had shown me for Gran Turismo 5, they had this rig set up that plugged into a car's electronics and got data from its driving on the track. Then the programmers would pull the usb flash stick and upload the data into a computer that compiled the data.

My brother has driven the new BRZ / GT86 (FT86) test production car, and he also has GT 5 on a PS3 and he says the handling, acceleration, etc is similar. He is really excited about this new car and is amazed how GT 5 gets the GT86's characteristics down (rear wheel drive, drift / skid factor, braking / handling, sound, etc).

The only thing missing is the G and feeling of momentum and motion, wheel tension, pedal pressure etc the real thing has.


The technology to record the actual flight data / getting experience pilots to work with is available, as there are some examples of the warbirds. For planes that don't have flyable model, and there isn't a pilot that flew in them when they were available . . . they'd just have to get a working one as close and go from the records / pilot records of how it responded.

But the thing is GT 5 had a Modern Warfare esque budget, and 1C doesn't have that . . .

Then you have to have the fun factor / time, and that cuts out the realism.
Where as in real, missions can take a long time / black widow planes will have quirks that will crash newb and intermediate pilots . . . even experienced fliers unaware of the ship he is flying . . . guns will jam.

So you could have sudden things uber realistic but it just robs the fun factor and people don't play. Now I know the hardcore guys and gals will say "No make it as realistic." but there even then they will find certain aspects modeled realistically won't work in the game.

So there is a balance between realism and fun.

But IL-2 is the sim that gets close. And the devs show they are willing to work to get it as close as possible.

[Gabelschwanz Teufel]

It wouldn't do any good to have someone with experience post their observations. There would be someone shouting them down because they're old and can't remember or the aircraft they're flying now is less weight that it was when used in combat, etc.

[mazex]

Originally Posted by Blackdog_kt

I think that technology-wise Xplane is probably the closest one can get to having a wind tunnel emulator running on a PC (as long as the individual flyable is also done to a high standard to take advantage of the sim's engine in full), but sadly it will be some time before we see such technology in combat sims: it's so taxing that with full multi-core support in Xplane 10, a current PC can not run more than 4-6 AI aircraft with the same FM accuracy at the same time without noticeable performance loss. In fact, there are people who take Xplane flyables, simplify their FMs and reissue them as AI-only aircraft to populate the game world.

P.S. Very interesting topic

I don't understand why X-Plane is so "hyped" - or have I missed to un-tick some default "arcade" setting?

Look at the clip below where I do my regular test of the FM in X-Plane (latest version 10). Some barrel rolls right after take off.

http://www.youtube.com/watch?v=ciJCTBW7zGc&hd=1

I'm sorry for being a bit evil in my comments

[robtek]

Do this with a 88 in cod and you're a smokin crater.

[ElAurens]

Originally Posted by CaptainDoggles

Interesting topic indeed!

I don't buy it though, or perhaps just not the car analogy.



If two cars have identical accelerations then they'll hit the same speed at the same time. Period. If the driver of one feels like he has to "bully" the car into doing it then that's his problem. Just a problem with his perception - because we already know the car is doing it just as well as the other car. If it didn't, then the accelerations would not be identical.

As far as this can relate to aircraft, well, I'm not sure what ElAurens is advocating exactly, but it does raise the issue of how to simulate what basically boils down to a pilot's opinion.

Being an engineer, my belief is that the nebulous qualities that we call "handling" or "feel" will show up when we consider things such as the aircraft's stability. For example the Spitfire was widely considered to be a forgiving aircraft but (test) pilots complained that the early versions "did not have enough elevator authority" and that it was difficult to control the aircraft, pitch-wise. When the issue was investigated it was found that the aircraft had a very narrow longitudinal stability margin.

I struggle to imagine a concept that can't be quantified, or related to some measurable quantity in some way.

Nothing personal Doggles, but I suspect you have never driven on a race track (road course). Two vehicles of similar performance can behave very differently and one can indeed be easy to extract it's performance from while the other is a workout to drive.

In a sim there is none of this.

They are all easy. And if they are not (rare) then players tweak thier joysticks or put trim on a slider, or what have you, to make them easy.